1. Technical Field
The embodiments herein generally relate to the field of wireless communication and particularly relates to method and system for acquiring system information messages in wireless communication systems. The embodiments herein more particularly relates to a method and system for acquiring modified system information messages in a user equipment.
2. Description of the Related Art
The Long Term Evolution (LTE) is a new terrestrial mobile communication standard currently being standardized by the 3GPP. The Radio Access Network (RAN) of LTE is named as the Evolved-Universal Mobile Telecommunication Systems Radio Access Network (E-UTRAN). The E-UTRAN physical layer is based on Orthogonal Frequency Division Multiplexing (OFDM). More precisely; the downlink transmission scheme is based on conventional. OFDM using a cyclic prefix while the uplink transmission is based on single carrier frequency division multiple access (SC-FDMA) techniques. The OFDM subcarrier spacing is 15 kHz in both uplink and downlink transmission. LTE supports both frequency division duplex (FDD) and time division duplex (TDD).
System Information (SI) in an LTE system is divided into a number of System Information Blocks (SIBs) and Master Information Block (MIB). The MIB includes limited number of most essential and frequently transmitted parameters to acquire other information from the cell. The SI is defined in TS 36.300 as a RRC message carrying a number of System Information Blocks (SIBs) that have the same periodicity. Each System Information Block (SIB) contains a set of related system information parameters. System Information BlockType1 (SIB1) is transmitted alone, separately from other SI-messages. The MIB message is mapped on a Broadcast Control Channel (BCCH) and carried on Physical Broadcast Channel (PBCH). All other SI messages are carried on a Downlink Shared Channel (DL-SCH) where they can be identified through the SI-RNTI (System Information Radio Network Temporary Identifier).
SIBs other than SIB1 are carried in SI messages and mapping of System Information Blocks to SI messages is flexibly configurable by using a scheduling Information parameter included in SIB1, with restrictions that each SIB is contained only in a single SI message. Only SIBs having the same scheduling (periodicity) requirement can be mapped to the same SI message. SystemInformationBlockType2 (SIB2) is always mapped to the SI message that corresponds to the first entry in the list of SI messages in the scheduling Information parameter.
In the event that modification of system information is desired, the network can undergo a system information modification procedure by which all. UEs communicating with the network, are informed of an impending change to the system information. However, in conventional implementations, a wireless communication network conveys only a generalized indicator of an upcoming change of system information to its respective served UEs without providing any further information relating to the information to be changed. As a result, UEs communicating with the network can in some cases be required to re-acquire all system information at each modification regardless of the information to be affected by a given modification. Such a requirement can, in turn, cause losses in UE and/or network, performance and power efficiency, an increase in UE implementation complexity, and/or other negative effects on respective UEs and/or an associated network.
Normally, during System information Modification procedure, the eNB transmits the modified System Information in the corresponding modification period. The UE is informed through Paging Procedure and/or SIB1 about the SI modification. But the UE does not know which SI has got modified. The UE acquires the new system information immediately from the next SI modification period. This procedure is inefficient since the UE will acquire all SI messages irrespective of whether the SI message has got modified or not.
In view of the foregoing, there exists a need for a method and system for managing a modification of system information messages associated with a wireless communication network that mitigates at least the above shortcomings. There also exists a need for a method and system for notifying an user equipment on a modification of the system information message in comparison to the previous system information modification cycle. Further, there exists a need to provide a system and method for acquiring modified system information messages in a user equipment.
The abovementioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.